Geomagnetic Variations Observed on the Earth’s Surface and Associated with Strong Earthquakes
С. А. Рябова, С. Л. Шалимов
Abstract
Abstract—The intensification of geomagnetic variations due to a number of strong remote earthquakes is studied using a chain of ground-based midlatitude magnetic stations located a few thousand km away from each other. It is shown that the spectral peaks of the variations at periods between 5 and 13 min (the range of magnetic pulsations Pc5–Pc6) can be caused by the corresponding variations in the components of the interplanetary magnetic field. Geomagnetic variations with periods longer than 13 min are interpreted as the result of the propagation of slow magnetohydrodynamic (MHD) waves excited in the ionosphere by acoustic pulse after earthquakes or as the result of the passage of traveling ionospheric disturbances.